Sidra Sayed, MA Counselling Psychology
Depression, as defined by the American Psychiatric Association, is a common but serious medical illness that negatively impacts the way someone thinks, acts, and feels. It can have a significant impact on one’s ability to function on a day-to-day basis. For an illness as common as depression, it’s no surprise that it comes with many misconceptions. As a result of this stigma, many living with depression will often blame themselves for how they feel. They tend to use inaccurate shorthand labels to describe their actions, which have been impacted by their mental health, rather than recognize the weight of the illness.
Current treatment methods tend to focus on helping an individual with depression feel better, given the toll that depression takes on their lives. While this is an important aspect of supporting these individuals, it is also important for them to understand what’s happening inside their bodies. Understanding how their brain works can actually help decrease self-blame and remove the stigma.
COMMON PERCEPTION OF DEPRESSION
Many people think of depression as an emotion or feeling, rather than an illness. This has become a buzzword and is loosely used to describe an individual experiencing lack of motivation and a low mood. However, like any other mental or physical illness, it is important to remember that depression has more to it than emotions and one’s behavior. This suggests that most people understand what depression looks like on the outside. Therefore, the aim of this article is to provide an inside look into the brain structure of an individual living with depression.
A Deeper dive into depression
Depression is one of the most common mood disorders reported. According to the National Institute of Mental Health, an estimated 21 million (8.4%) American adults suffered from at least one major depressive episode in 2020. Similarly, about 5.4% of the Canadian population is affected by major depression. To further understand why it is such a prevalent illness, the American Psychiatric Association (APA) has explored various factors that can be linked to causing depression. These factors include but are not limited to stress, socioeconomic factors, traumatic life experiences, number of episodes, course modifiers, and genetics. With respect to genetics, the APA suggests that if an immediate family member has depression, an individual is 2 to 4 times more likely to develop the illness.
Stanford Medicine suggests that heritability accounts for 40% to 50% of depression. This indicates a strong relationship between genetics and depression.
The empirical data accounts for what is happening inside the body of an individual with depression. This emphasizes the importance of understanding the biological makeup of a patient, to support and empower them to break the cycle of self-blame and remove the stigma around the illness.
Brain structure
We’ve seen that depression and brain structure are strongly correlated. Here are 3 major areas of the brain that play a role in depression.
1. HIPpocampus
The hippocampus is an important part of the limbic system and is the most studied brain region in relation to depression as it is responsible for memory and emotion. Numerous studies have linked substantial reduction in hippocampal volume with depression. Volumetric change may be due to a neurodegenerative response to heightened glucocorticoid levels in depression. In addition to that, the alteration in synaptic plasticity prompted by depression is linked with structural and functional changes in the hippocampus.
It is important to note that the severity of depression is not dependent on the hippocampal volumetric change. Rather, science has illustrated that faster recovery of depression may be seen in those with larger hippocampal volumes. Lower hippocampal volume functions as an indicator of depressive episodes or depression.
2. PREFRONTAL CORTEX
The prefrontal cortex refers to the cerebral cortex, which covers the front part of the frontal lobe. This area of the brain is responsible for carrying out the executive function. The term executive function refers to complex cognitive functions such as decision making, problem-solving, and self-control.
The prefrontal cortex, which is responsible for thinking and regulation in the brain is also related to depression. Structurally speaking, the prefrontal cortex is divided into two parts: the ventromedial prefrontal cortex (vmPFC) and dorsolateral sectors (d1PFC). VmPFC accounts for negative emotions and regulation of affection, and d1PFC facilitates cognitive functions. A review article explains that functional imaging has demonstrated the opposite change within these two parts of the brain during the progression of depression. Meaning, as the depression progresses, overactivity was visible in the vmPFC, whereas under activity was present in d1PFC.
Research has established that those with depression show extremely low activity in the prefrontal cortex. Therefore, we can note that the severity of depression is often a reflection of the weakening activity in one’s prefrontal cortex.
3. AMYGDALA
The amygdala is one of the regions of the brain that is primarily associated with regulating emotions. It has been found that the amygdala is often significantly more active in individuals with depression. For example, when presented with negative stimuli, such as a sad face, those with depression are likely to have a much more active amygdala than those without depression. However, there is little change if a positive stimulus is presented. This indicates that individuals with depression process positive and negative stimuli differently, suggesting that the two brains may have something to do with increased levels of cortisol (stress hormone). Learn more about how stress impacts your brain and body, in a previous blog post.
For those living with depression, the stress hormone remains active all day, which is draining to the body and may result in neurotransmitters such as serotonin (also referred to as “feel-good hormone”) shutting down. It is important to consider that stress alone does not lead to depression. It is rather the inability to cope with the stress that is a determinant factor. The ability to deal with stress relies on the vmPFC found in the prefrontal cortex. Meaning, if the stressor is manageable then the vmPFC helps the amygdala in becoming inactive. However, if it is uncontrollable then the activation in the amygdala increases, leading to excessive negative mood.
The difference in brain structure between a depressed brain and a non-depressed brain still presents a lot of unanswered questions. Is the altered brain structure causing depression or is the alteration in the brain a result of depression? These are questions that still require further investigation by scientists in the hope to better equip health professionals. By increasing our understanding of the illness, we are one step closer to dismantling the stigma. To learn more about brain structure in depressed patients, take a look at some of the additional resources below.
Neurovine is aiming to empower patients to take control of their recovery. To find out more or get involved, give us a call, email, or contact us. We look forward to hearing from you!
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